Fuzzy Control Approach to Reconfigurable Manufacturing System Involving Equipment Representation

A systematic approach for responsiveness assessment for product and material flow in reconfigurable manufacturing system (RMS)

Dynamic and unpredictable market changes have brought more challenges to manufacturers. Manufacturers are required to design their production process with the ability not only to meet changing customer demands dynamically, but also to produce quality products at low cost and to stay sustainable by decreasing the emission and energy consumption. The reconfigurable manufacturing system (RMS) appeared as a promising solution to cope with rapidly changing market demands. The RMS has the ability to satisfy the demand by quickly adapting (removing, adding, adjusting, changing) parts, which highly consider the set of machines, as known as reconfiguration in RMS. The RMS also has the capability to increase companies profit by optimizing its reconfiguration process where product family formation is crucial. However, in sustainability, three main parts need to be satisfied, which are social, economic, and environmental. The RMS is still lack in the environmental area. In order to increase the sustainability of RMS, Green Bill of Material (Green-BOM) is used as a supporting tool to maintain the eco-friendliness of each part/product. In this paper, product family formation is introduced to represent the main problem of reconfiguration process, and Green-BOM is introduced to maintain the sustainability within RMS. However, there is still lack of discussion or researches regarding sustainability within RMS. Therefore, a systematic approach is discussed by featuring Green Bill of Material (Green-BOM) to maintain sustainability within products and during product family formation

Consideration for the energy consumption and environmental impacts is required depending on the changed capacity under a flexible and reconfigurable manufacturing environment. This article focuses on a holistic production planning approach in a reconfigurable manufacturing system. The energy consumption and material flows that are incurred on the reconfigurable manufacturing system are defined from the perspective of the processing plan describing how to make a part. The suggested energy estimation model integrates the existing literature and set up a newly modified model including diverse part handling systems such as automated guided vehicle and conveyor in more detail. Alternative system reconfigurations are analysed in order to dynamically evaluate the performance in terms of different holistic criteria such as the energy consumption, environmental effects and throughput. A production planning model with the multi-objective function for minimising the energy consumption and maximising the throughput is developed. The benefit coming from the adoption of suggested model has been addressed with reference to a real industrial use case study.

PurposeA reconfigurable manufacturing system (RMS) can provide manufacturing flexibility, meet changing market demands and deliver high performance, among other benefits. However, adoption and performance improvement are critical activities in it. The current study aims to identify the important factors influencing RMS adoption and validate a conceptual model as well as develop a structural model for the identified factors.Design/methodology/approachAn extensive review of RMS articles was conducted to identify the eight factors and 47 sub-factors that are relevant to RMS adoption and performance improvement. For these factors, a conceptual framework was developed as well as research hypotheses were framed. A questionnaire was developed, and 117 responses from national and international domain experts were collected. To validate the developed framework and test the research hypothesis, structural equation modeling was used, with software tools SPSS and AMOS.FindingsThe findings support six hypotheses: “advanced technologies,” “quality and safety practice,” “strategy and policy practice,” “organizational practices,” “process management practices,” and “soft computing practices.” All of the supported hypotheses have a positive impact on RMS adoption. However, the two more positive hypotheses, namely, “sustainability practices” and “human resource policies,” were not supported in the analysis, highlighting the need for greater awareness of them in the manufacturing community.Research limitations/implicationsThe current study is limited to the 47 identified factors; however, these factors can be further explored and more sub-factors identified, which are not taken into account in this study.Practical implicationsManagers and practitioners can use the current work’s findings to develop effective RMS implementation strategies. The results can also be used to improve the manufacturing system’s performance and identify the source of poor performance.Originality/valueThis paper identifies critical RMS adoption factors and demonstrates an effective structural-based modeling method. This can be used in a variety of fields to assist policymakers and practitioners in selecting and implementing the best manufacturing system.Graphical abstract

An Overview of Performance Measures in Reconfigurable Manufacturing System

Currently, manufacturers seek to provide customized and sustainable products, requiring flexible manufacturing systems and advanced production management to cope with customization complexity and improve environmental performance. The reconfigurable manufacturing system (RMS) is expected to provide cost-effective customization in high responsiveness. However, reconfiguration optimization to produce sustainable mass-customized products in RMS is a complex problem requiring multi-criteria decision making. It is related to three problems, process planning, scheduling, and layout optimization, which should be integrated to optimize the RMS performance. This paper aims at integrating the above three problems and developing an effective approach to solving them concurrently. It formulates a multi-objective mathematical model simultaneously optimizing process planning, job-shop scheduling, and open-field layout problem to improve RMS sustainability. The penalty for product tardiness, the total manufacturing cost, the hazardous waste, and the greenhouse gases emissions are minimized. Economic and environmental indicators are defined to modify the Pareto efficiency when searching the Pareto-optimal solutions. Exact Pareto-optimal solutions are obtained by brute-force search and compared with those of the non-environmental indicator model. NSGA-III is adopted to obtain the approximate Pareto-optimal solutions in high effectiveness and efficiency. A small numerical example is applied to validate the mathematical model and resolution methods.

This work proposes a supervisory control method for reconfigurable manufacturing systems (RMSs) based on net condition/event systems (NCESs) under the firing rule `maximal single spontaneous transition steps'. It is assumed that the occurrence of a reconfiguration event changes the system configuration immediately and a reconfiguration requirement is triggered randomly in the current work. For the safety of an RMS, the implementation of system reconfigurations is only permitted at some specific plant states. However, it is unreasonable to execute a system reconfiguration immediately at a reconfigurable state, when current on-going manufacturing tasks are not finished. In order to keep the continuity of production process and to avoid confusion of an RMS, a novel reconfiguration control structure based on NCESs is proposed, where a reconfiguration controller (RC) performs the implementation of reconfigurations and a task supervisor (TS) monitors the execution status of tasks. The applicability of the method is illustrated by using a simple RMS.

Agent paradigm is a technology recognized as potent tool for the 21 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> century manufacturing system. Researches are on-going in the applications of agent technology to manufacturing enterprise, production process planning and scheduling, shop floor control, and to reconfigurable manufacturing system as an implementation case study. The article presents the results of a review of published articles on agents' usage at manufacturing enterprise level for reconfigurable manufacturing system between year 2003 and August, 2014 to provide up to date pictures of the technological function of agents and multi agents within the reconfigurable conceptualized manufacturing circles. The paper is viewed from the angle of wide coverage, broad scope of multi-agent techniques and a focus on real world applications. The outcomes include trends of agents and multi-agents usage in manufacturing enterprise resource planning, supply chain managements and the gaps yet to be filled for consolidating future plans on Industry 4.0 in reconfigurable manufacturing system.

th centrury, the concept of reconfigurable manufacturing systems (RMSs) rocked the world of manufacturing and promised a global revolution in the 21 st century manufacturing landscape. Since then, a lot of research on RMSs was conducted and numerous research papers were archived. In addition, a number of international conferences, workshops and seminars were organized to discuss, share and exchange highly focused, technical, and cutting edge theoretical research results and perspectives on RMSs. While a lot of research works are commendable, the realization of a true reconfigurable manufacturing system (RMS) is still elusive [1]. Consequently, a gap between archived theory - academia and practical realization - industry exists to date. This gap has lead to ‘doubts’ and ‘disquiet’ with respect to limitations, practicality and applicability of reconfigurable manufacturing concepts and techniques. In order to create a platform for bridging this gap, this paper suggests some answers to the question; “what can industrial engineering and management do to prevent reconfigurable manufacturing concepts from being yet another archived buzz word?”Perspectives and discussions which follow attempt to provoke industry, students, academia and researchers into high quality and highly valuable discussions aimed at redeeming and advancing RMSs concepts and techniques towards the realization of the full benefits of true reconfigurable manufacturing systems. Such discussions can be facilitated through this Industrial Engineering and Management journal by the Omics group. The term reconfigurable manufacturing systems can be attributed to Dr. Koren who, with other researchers at the Engineering Research Center for Reconfigurable Manufacturing Systems (ERC/RMS) at the University of Michigan, College of Engineering, invented or initiated the concept of an RMS as early as 1995. Since then, a repository of reconfiguration science has been accumulated. The repercussions of this invention went as far as forcing changes in the engineering curricula at the University of Michigan to integrate reconfigurable manufacturing concepts and techniques. However, to date only isolated “islands” of reconfiguration based technologies have been implemented in the following areas; controls, inspection, sensing, machines and machine tools. With the seemingly ‘disquiet’ and relatively less ‘enthusiasm’ on the part of both industry and academia, there is an imminent danger of collapse and relapse of the novel ideas of reconfigurable manufacturing. It is now the time to use industrial engineering and management tools and techniques to combine the various “islands” of reconfigurable manufacturing technologies scattered in various databases in a bid to develop and advanced current research results towards the realization of true reconfigurable manufacturing systems.

This correspondence presents the application of an existing deadlock-free resource allocation control method for a reconfigurable manufacturing system (RMS) with serial and parallel configuration, and further proposes a new higher level deadlock avoidance control method. RMSs have been introduced to replace traditional large-volume production systems such as dedicated manufacturing systems, adding more flexibility and convertibility. Such manufacturing systems require that their controls be changed rapidly to cope with unpredictable market demands; their desired control behaviors must also be verified in advance of running the system to reduce the ramp-up time. One important desired control behavior is the deadlock freeness in the resource allocation. A rule-based matrix method that has been proposed to develop deadlock-free resource allocation control is applied to an example RMS with serial and parallel configuration. Through this application, higher level deadlocks were found in the example RMS that are not prevented with the existing method. A new control method to avoid the higher level deadlocks is developed.

The reconfigurable manufacturing systems (RMSs) is the next step in manufacturing, allowing the production of any quantity of highly customised and complex parts together with the benefits of mass production. In RMSs, parts are grouped into families, each of which requires a specific system configuration. Initially system is configured to produce the first family of parts. Once it is finished, the system is reconfigured in order to produce the second family, and so forth. The effectiveness of a RMS depends on the formation of the optimum set of part families addressing various reconfigurability issues. The aim of this work is to establish a methodology for grouping parts into families for effective working of reconfigurable manufacturing systems (RMSs). The methodology carried out in two phases. In the first phase, the correlation matrix is used as similarity coefficient matrix to form the part operational similarity followed by agglomerative hierarchical K-means algorithm used for the parts family formation. In the second phase, cost model is developed to select and sequence the formed part families, resulting in a minimum cost solution to the problem.

A New Hybrid Approach for Machine Layout Design Under Family Product Evolution for Reconfigurable Manufacturing Systems

Reconfigurable Manufacturing Systems (RMS) have been an increasing area of interest in the research arena. However, it seems that current literature is lacking application and implementation cases where RMS are simulated, tested, and evaluated as a feasible manufacturing concept. A Manufacturer of Consumer Goods identified the potential of the RMS concept and decided to investigate the concept in a real production installation. The result of this development is a proof of concept of a changeable and reconfigurable assembly and decoration system based on the principles of RMS. This proof of concept is meant primarily to show the physical feasibility of the system and provide a first-look into a real production application of the RMS ideas. The purpose of this paper is to present the design of the manufacturer’s RMS proof of concept, its implementation, and evaluation results.

The reconfigurable manufacturing system (RMS) is an advanced manufacturing strategy that enables precise adjustment of functionality and capacity to meet fluctuating demands economically. RMS focuses on part families, allowing configurations to be adapted for new part requirements. Optimizing flow line design to produce various parts involves minimizing reconfigurations and associated costs by enhancing operation sequence similarity. This article proposes a novel sequence optimization using the Longest Common Subsequence (LCS) method to reduce bypassing moves and machine idle times. The study introduces a similarity coefficient derived from LCS and employs average linkage hierarchical clustering to categorize parts in a case study. Unlike traditional methods, this approach considers material movements both before the initial machine and after the final processing station, addressing gaps in bypassing move calculations. The impact of different weighting scenarios for Type-II moves (ω) and machine idleness (β) on clustering was examined. For example, with Type-II move weights (ω) of {1.0, 0.6, 0.3, 0.0} and equal weightings for bypassing moves (α) and machine idleness (β) set at 0.5, a threshold value of 0.3 results in eight clusters, such as Cluster 1 {1, 11, 10, 12} and Cluster 3 {3, 5, 6, 4, 15, 9, 13, 14, 7, 8}. Lower threshold values lead to fewer clusters with larger sizes, indicating a more consolidated part family grouping. Various Type-II move weights and material handling scenarios demonstrate how different weighting configurations affect clustering and part family sizes. This approach enhances RMS efficiency by integrating comprehensive material handling considerations and optimizing clustering based on operational similarities.

The problem of optimizing modular products in a reconfigurable manufacturing system is addressed. The problem is first posed as a generalized subset selection problem where the best subsets of module instances of unknown sizes are determined by minimizing an objective function that represents a trade-off between “the quality loss due to modularization” and the cost of reconfiguration while satisfying the problem constraints. The problem is then formulated and solved as an integer nonlinear programming problem with binary variables. The proposed method is applied to the production of a modular drive system composed of a DC motor and a ball screw. The study is a first attempt toward developing a systematic methodology for manufacturing modular products in a reconfigurable manufacturing system.